1. Field of the Invention
This invention relates to adjustable furniture and in particular concerns adjustable beds having adjustable body-support sections which can be moved to adjust the position of a user.
2. Description of the Related Art
Adjustable beds are known for example from US2009/0193587 which discloses an adjustable bed in which a back/head support section and leg/foot support sections are pivotably mounted next to a fixed intermediate support section. Electrical linear actuators are attached to the underside of both the back and leg support sections for moving those sections between horizontal and inclined positions. The linear actuators act more-or-less directly on the underside of the moveable body support portions. Each of the body support sections is provided with a flexible cushion and in order to prevent crushing of the adjacent ends of the respective cushions, during adjustment of the bed, the bed includes independently moveable front and rear carriages powered by linear actuators supported on a stationary base. The back/head support section is pivotally secured to one carriage and moves linearly with it. The leg and foot support sections are pivotally connected together and are supported by the other carriage and move with it. This arrangement prevents crushing of the respective cushions and adjacent parts of a support mattress supported on the cushions in use, that is when the bed is raised from the lying flat position to its raised position.
The adjustable bed disclosed in US2009/0193587 provides a solution to the problem of compression of the adjoining edges of the adjacent body support cushions due to compression points being developed when the respective sections of the bed are moved to their raised positions. This arrangement requires a minimum of four linear actuators, one each for moving the pivotable parts of the bed and one for each moveable carriage. The moveable front and rear carriages and associated actuators adds considerable cost and weight to the adjustable bed. This and other known adjustable bed arrangements are mechanically complex and expensive to manufacture. There is a requirement therefore for a lighter and less expensive adjustment mechanism for articles of adjustable furniture having sufficient strength, weight carrying capacity and durability.